Which is better: biodegradable or compostable?
But before we get into the fight, what exactly does compostable mean? What’s the distinction between biodegradable and compostable?
Both names indicate matter disintegration, but misunderstandings about their underlying distinctions produce a slew of issues when it comes to safe disposal.
While the terms “compostable” and “biodegradable” are sometimes used wrongly and interchangeably, they are not synonymous. It’s past time for us, as conscious consumers and zero-waste advocates, to understand the distinction.
Without further ado, let’s see how compostable and biodegradable materials fare in the muck.
1. What Does the Term “Biodegradable” Mean?
Before we get into biodegradability, let’s look at the word’s root: degradable.
Biodegradable vs. degradable
Every product on the planet is technically degradable since it will ultimately degrade, either biologically or chemically.
Meanwhile, a biodegradable product is one that will be broken down by organisms or bacteria.
Traditional petroleum-based plastics, as well as other heavy metal and chemical-based materials, are degradable but not biodegradable.
They never entirely degrade into their natural elements to be recycled by the planet; instead, they break down into smaller bits over time.
Plastics are the worst culprits because they degrade into smaller fragments, known as microplastics, when exposed to sunshine.
Microplastics, on the other hand, are polluting every corner of the world, including fresh snow in Antarctica and even human lungs, placenta, and breast milk.
Plastic pollution has recently been named a worldwide issue by the United Nations.
Biodegradable materials are being broken down.
At its most fundamental, biodegradation is the breakdown of something into its natural parts (water, carbon dioxide, and biomass).
The same is true for solid or liquid waste that enters water systems (such as natural shampoo or eco-friendly cleaning products).
This degradation is carried out by naturally occurring microorganisms such as bacteria and fungi in a proper temperature, moisture, and oxygenation environment.
When you consider the time required to do this task, things become more complicated.
The rate at which a material biodegrades (which might range from several months to forever) is determined by its surroundings. Not everything biodegradable degrades in a fair length of time in any area.
Landfills, for example, not only stifle biodegradation but also contaminate it with harmful substances. Items biodegrade anaerobically (without oxygen) in landfills, producing massive volumes of methane, a GHG 25 times more potent than CO2.
Despite the fact that trillions of pieces of rubbish populate the oceans, they also provide an insufficient environment for biodegradability.
The worldwide marine litter research team at the University of Plymouth discovered that biodegradable plastic bags were generally unharmed and could still retain significant weight three years after being left in seawater OR buried.
As a result, there is no common legal definition of what makes a completely biodegradable product. As a result, consumers are frequently confronted with labeling that is completely worthless.
So, what’s the big deal about products that are biodegradable?
Biodegradability became a buzzword in the 1980s.
Particularly since biodegradability was not fully established until 2002, that’s two decades of unqualified assertions that have led consumers to believe they are being ecologically responsible.
Fortunately, we now have scientific ways of determining if something may biodegrade without leaving hazardous residue.
Technology has also enabled the adaptation of organic materials to operate identically to plastic packaging. These are referred to as bioplastics.
Bioplastics, as opposed to typical petrochemical-based plastics, are derived from plant-based materials:
- Cellophane: wood (one of the first plastics ever created)
- PLA (Polylactic Acid): a type of vegetable starch
- Plutarch (PSM) is a blend of plant starch and polypropylene.
- Mater-Bi is a plant starch.
Being plant-based, on the other hand, does not ensure a positive end-of-life outcome.
Many bioplastics function similarly to normal plastics and take millennia to degrade.
They cannot be recycled, should not be disposed of in landfills since their organic composition will emit methane gas, and should only be delivered to an industrial composting facility—of which there are only 185 full-scale operations in the United States as of 2018.
There are two more major myths about biodegradable materials:
FTC regulations only require that biodegradable products degrade, not that they leave no hazardous behind.
Many companies combine bioplastic and ordinary plastic with the cunning disclaimer “made WITH biodegradable plastic.” The FTC can’t do anything because they’re not technically calling it biodegradable.
It’s no surprise that environmentalists are rapidly abandoning the word due to widespread greenwashing and misapplication. Plastic packaging branded “biodegradable” is currently unlawful in the state of California.
So, where does that leave us in the debate between biodegradable and compostable plastic?
Remember that conscientious packaging is one of the most important sustainable product criteria. Ideally, it should be zero waste, which means it should be bare, reusable, or biodegradable. Hmm…nothing about biodegradable…
2. What Does the Term “Compostable” Mean?
Composting promotes biodegradation by balancing moisture, temperature, and oxygenation to enhance microbial action. Consider compostability to be the gold criterion of biodegradation.
Biodegradable items are, by definition, compostable, but not all biodegradable products match the narrower compostable criteria.
While biodegradation might take months to 10,000 years, composting typically takes 12 weeks—hence the essential distinction between compostable and biodegradable.
Composting must also take place in soil, a compost heap, indoor compost bins, or commercial composters rather than in landfills, natural streams, or seas.
Compostable products, unlike normal biodegradability criteria, must also degrade into fully non-toxic components.
Even natural materials can be rendered non-compostable during the production process by additions.
Lumber is an excellent example. While wood is completely biological, it is frequently treated with hazardous chemicals that leave poisonous waste and prevent it from decomposing safely into “usable compost.”
Home compostability guidelines
In addition to decomposing into useable compost, FTC guidelines require home compostable items to degrade in a “safe and timely manner.”
A safe timescale for defining biodegradable products is the same as any other compostable materials that are composted with it.
Consider compostable versus biodegradable waste bags.
If it’s going in a home compost pile with food scraps that biodegrade in half the time, a bag that meets all other compostability criteria isn’t compostable.
Because a home compost environment does not achieve high enough temperatures to break things down quickly, definitions of home composting are significantly more limited.
The following are some examples of home compostable materials:
- Fruits, vegetables, peelings, bread, cereal, coffee grounds, crushed eggshells, tea leaves, and tea bags (but no basics) are all acceptable.
- Clippings of leaves, grass, and foliage
- Dry cat or dog food made with wine
- Sweeping and vacuuming dust
- Herbs and spices from the past
- Shredded paper or cardboard (no coatings, wax, or glue allowed)
- Items that may disrupt the pH balance, take longer than 6 months to degrade, or emit microplastics should be avoided.
Bioplastic packaging, biodegradable bags, biodegradable products, compostable bags, compostable food carriers, dryer lint, pet feces, eco-friendly cat litter, fish bones, meat, animal bones, milk, cheese, oils, or butter are not compostable at home.
Commercial composting facilities may break down these complicated items due to higher temperatures and technology that breaks things down into small pieces.
According to FTC guidelines, marketing and packaging must specify where something is supposed to be composted and mention clearly if it cannot be composted at home.
3. What Is the Difference Between 100% Biodegradable and Compostable?
Yes, if we’re talking about pure organic materials, but no, because the term “biodegradable” is rarely given to such objects.
There are significant differences between biodegradable and compostable packaging or plastic, particularly when it comes to crucial ingredients.
These include the rate of disintegration and the requirement to “leave no toxic residue”—which, in the case of biodegradable plastics, is mostly a lie that contributes to our microplastic catastrophe.
Plastic bags that degrade versus those that compost
Because there is a “blind embrace” that biodegradable = good, we find biodegradable materials causing greater harm in landfills, as they wrongly break down, producing microplastics and methane.
Many bioplastics aren’t even biodegradable, and while being plant-based, they “can be designed to be structurally identical to petroleum-based plastics.”
Without regulatory guidelines for what is labeled as bioplastic or biobased (heck, even 100% petroleum-based polymers can be labeled biobased! ), it’s reasonable to say that most biodegradable items are a scam.
We recommend avoiding single-use biodegradable items entirely until further study, development, education, and management are handled.
How about biodegradable packaging and products?
Unfortunately, due to a lack of education and infrastructure, compostable plastics are also problematic. In the United Kingdom, 90% of compostable products wind up in landfills, and 60% do not degrade within 6 months.
“The bottom line is that home compostable plastics don’t work,” argues Professor Mark Miodownik, co-author of “The Compost Experiment.” Let’s just call it a day. Let us not kid ourselves that technology will be a panacea and that you can sell people things without having the infrastructure to deal with the garbage and expect that it would all go away.”
4. Biodegradable and compostable: Scientific testing, legal standards, and certifications
Biobased, bioplastic, degradable, biodegradable, and compostable are not synonymous, and with few legally binding global regulations, there is no accountability behind these terms depending on where you are in the world.
United States and Canada:
The Federal Trade Commission has some enforceable laws around labeling to prevent greenwashing, as well as a handy guide on environmental marketing claims in the United States and Canada.
The FTC’s guidelines include the following:
Biodegradability requires that the entire product or package “completely break down and return to nature within a reasonably short period of time [one year] after customary disposal,” as demonstrated by solid scientific data.
Compostability: The item decomposes in the same amount of time as the other compost, up to 180 days.
Europe:
There is no certification for biodegradability in the EU, although there are two standard compostability measures:
EN 13432: Requirements for biodegradable packaging polymers to totally break down in an industrial composting operation.
EN 14995: An extension of the previous standard for polymers used outside of product packaging.
Both criteria specify the rate of microbial activity (90% biodegradation in 6 months), final fragment size, ecotoxicity, and chemical analysis (no more than 1% environmentally innocuous substances and additions).
However, the rules are not legally binding in Europe, and there is no requirement to disclose how much bio-based material is in a product.
New Zealand and Australia:
Australasian Bioplastics has two standards, one for industrial compost of biodegradable material and one for home composting:
AS 4736-2006: The general standard of commercially compostable and biodegradable plastic.
AS 5810-2010: Verification of all products (including plastics) that can be composted at home. It needs to disintegrate in six months and biodegrade completely in a year.
Last Words on Biodegradability and Compostability
In conclusion, does compostable imply biodegradable?
No, and we propose that you avoid the hazy biodegradable labeling in favor of organic, compostable products.
However, biodegradable and compostable plastics and bags fall short of providing the needed solution to our single-use addiction.
The most important thing is to refuse, reduce, and reuse where possible. If you do choose these goods, make sure you have the tools to properly dispose of them.
Understanding the differences between compostable, biodegradable, and recyclable materials is essential if we want to be more conscientious consumers because we should always buy items knowing what we’ll do with them after they’re no longer functioning.
So, read labels with caution, check for certificates, and share this article so that more people realize the fundamental distinctions between biodegradable and compostable items.